in this video we'll take a look at whether you should report P is less than
.05 or P is greater than .05 in a given situation. In
hypothesis testing a common question I receive as I said before is whether
state P is less than .05 or P is greater than .05. The
answer to this question is it really depends. It depends on whether the
results are statistically significant or not. Let's go ahead and take a look at
this next. So suppose that we ran a statistical test and we obtained results
that were statistically significant. If this was the case then we would reject
the null hypothesis. So when the results are statistically significant we state P
is less than .05 or in other words when we reject the null hypothesis
we state P is less than .05 and this assumes that an alpha of 0.05
is used when we use an alpha .05 that's why we state P is less than
0.05 if we used an alpha .01 and the test was statistically
significant then we would say P is less than .01 and for those who
are interested we'll get into the technical details about why we state P
is less than .05 in just a few moments. So in summary for
statistically significant results we want to state P is less than .05.
If, on the other hand, we obtained results that were not statistically
significant, we would fail to reject the null hypothesis. When the results are not
statistically significant we state P is greater than .05.
So, in summary, for non significant results we state P is greater than
.05. Technically speaking the p value like when we state P is less than
.05 it indicates the probability and that's what P stands for
probability of getting our results or results even more extreme if the null
hypothesis was true. When we say P is less than .05, we're
declaring that the probability of getting the results we obtained is less
than .05 or five percent if the null hypothesis was true and this
makes the results significant as it occurs less than five percent of the
time by chance alone. So this is why we state, with significant results, that P is
less than .05, because the chance or probability of getting such
results is less than five percent. On the other hand getting non
significant results indicates that the probability of getting the specific
results we obtained is greater than .05 or five percent if the
null hypothesis was true. This is why with non significant results we say P is
greater than .05 because the chance of getting such results is
greater than five percent. If you've gotten this wrong or been confused about
this before don't be discouraged as this is one of the most common questions or
really mistakes that I see made in statistics I get a lot of questions
about this and a lot of people get it backwards so just try to remember here
four significant results you want to say P is less than .05 and this
is when you reject the null hypothesis so if you get statistically significant
results you put P is less than .05 and then for non significant
results you just put the opposite P is greater than .05 and in this
case this is when you fail to reject the null or you accept the null as some
people say and just as a reminder if you were to use alpha .01 then
you would say P is less than .01 or P is greater than .01
depending on whether you got significant or non significant results, respectively.
Okay that's it; thanks for watching.